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Create View
CREATE VIEW creates a view with the given name. An error is thrown if a table or view with the same name already exists. You can use IF NOT EXISTS to skip the error. If no column names are supplied, the names of the view's columns will be derived automatically from the defining SELECT expression. (If the SELECT contains unaliased scalar expressions such as x+y, the resulting view column names will be generated in the form _C0, _C1, etc.) When renaming columns, column comments can also optionally be supplied. (Comments are not automatically inherited from underlying columns.) A CREATE VIEW statement will fail if the view's defining SELECT expression is invalid. Note that a view is a purely logical object with no associated storage. (No support for materialized views is currently available in Hive.) When a query references a view, the view's definition is evaluated in order to produce a set of rows for further processing by the query. (This is a conceptual description; in fact, as part of query optimization, Hive may combine the view's definition with the query's, e.g. pushing filters from the query down into the view.) A view's schema is frozen at the time the view is created; subsequent changes to underlying tables (e.g. adding a column) will not be reflected in the view's schema. If an underlying table is dropped or changed in an incompatible fashion, subsequent attempts to query the invalid view will fail. Views are read-only and may not be used as the target of LOAD/INSERT/ALTER. For changing metadata, see ALTER VIEW. A view may contain ORDER BY and LIMIT clauses. If a referencing query also contains these clauses, the query-level clauses are evaluated after the view clauses (and after any other operations in the query). For example, if a view specifies LIMIT 5, and a referencing query is executed as (select * from v LIMIT 10), then at most 5 rows will be returned. Starting with Hive 0.13.0, the view's select statement can include one or more common table expressions (CTEs) as shown in the SELECT syntax. For examples of CTEs in CREATE VIEW statements, see Common Table Expression.
Use SHOW CREATE TABLE to display the CREATE VIEW statement that created a view. As of Hive 2.2.0, SHOW VIEWS displays a list of views in a database.
Drop View
DROP VIEW removes metadata for the specified view. (It is illegal to use DROP TABLE on a view.) When dropping a view referenced by other views, no warning is given (the dependent views are left dangling as invalid and must be dropped or recreated by the user). In Hive 0.7.0 or later, DROP returns an error if the view doesn't exist, unless IF EXISTS is specified or the configuration variable hive.exec.drop.ignorenonexistent is set to true.
Alter View Properties
As with ALTER TABLE, you can use this statement to add your own metadata to a view. Alter View As Select
Alter View As Select changes the definition of a view, which must exist. The syntax is similar to that for CREATE VIEW and the effect is the same as for CREATE OR REPLACE VIEW. Note: The view must already exist, and if the view has partitions, it could not be replaced by Alter View As Select. |
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These statements provide a way to query the Hive metastore for existing data and metadata accessible to this Hive system. Show Databases
SHOW DATABASES or SHOW SCHEMAS lists all of the databases defined in the metastore. The uses of SCHEMAS and DATABASES are interchangeable – they mean the same thing. The optional LIKE clause allows the list of databases to be filtered using a regular expression. Wildcards in the regular expression can only be '*' for any character(s) or '|' for a choice. Examples are 'employees', 'emp*', 'emp*|*ees', all of which will match the database named 'employees'.
Show Tables/Views/Partitions/IndexesShow Tables
Show Views
Show Partitions
SHOW PARTITIONS lists all the existing partitions for a given base table. Partitions are listed in alphabetical order.
It is also possible to specify parts of a partition specification to filter the resulting list.
Show Table/Partition Extended
SHOW TABLE EXTENDED will list information for all tables matching the given regular expression. Users cannot use regular expression for table name if a partition specification is present. This command's output includes basic table information and file system information like totalNumberFiles, totalFileSize, maxFileSize, minFileSize,lastAccessTime, and lastUpdateTime. If partition is present, it will output the given partition's file system information instead of table's file system information.
Show Table Properties
The first form lists all of the table properties for the table in question one per row separated by tabs. The second form of the command prints only the value for the property that's being asked for. Show Create Table
SHOW CREATE TABLE shows the CREATE TABLE statement that creates a given table, or the CREATE VIEW statement that creates a given view. Show Indexes
SHOW INDEXES shows all of the indexes on a certain column, as well as information about them: index name, table name, names of the columns used as keys, index table name, index type, and comment. If the FORMATTED keyword is used, then column titles are printed for each column. Show Columns
SHOW COLUMNS shows all the columns in a table including partition columns. Show Functions
SHOW FUNCTIONS lists all the user defined and builtin functions matching the regular expression. To get all functions use ".*" Show Granted Roles and PrivilegesHive Default Authorization - Legacy Mode has information about these SHOW statements: In Hive 0.13.0 and later releases, SQL standard based authorization has these SHOW statements: Show Locks
SHOW LOCKS displays the locks on a table or partition. See Hive Concurrency Model for information about locks. SHOW LOCKS (DATABASE|SCHEMA) is supported from Hive 0.13 for DATABASE (see HIVE-2093) and Hive 0.14 for SCHEMA (see HIVE-6601). SCHEMA and DATABASE are interchangeable – they mean the same thing. When Hive transactions are being used, SHOW LOCKS returns this information (see HIVE-6460):
Show Conf
SHOW CONF returns a description of the specified configuration property.
Note that SHOW CONF does not show the current value of a configuration property. For current property settings, use the "set" command in the CLI or a HiveQL script (see Commands) or in Beeline (see Beeline Hive Commands). Show Transactions
SHOW TRANSACTIONS is for use by administrators when Hive transactions are being used. It returns a list of all currently open and aborted transactions in the system, including this information:
Show Compactions
SHOW COMPACTIONS returns a list of all tables and partitions currently being compacted or scheduled for compaction when Hive transactions are being used, including this information:
Compactions are initiated automatically, but can also be initiated manually with an ALTER TABLE COMPACT statement. |
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